The flexural cracking behavior of ultrahigh performance concrete (UHPC) beams was experimentally studied in this paper. Eight UHPC beams were tested and analyzed regarding their crack pattern, crack spacing and load‐crack width curves. The test variables included reinforcement ratio, reinforcement diameter and UHPC cover thickness. The results indicated that crack width of UHPC increased linearly with the increase of applied load until the yielding of steel rebars. When the applied load was beyond the yielding load, one or two flexural cracks developed into localized cracks, followed by a rapid increase in crack width. Besides, increasing the ratio of steel rebars and appropriately decreasing the thickness of UHPC cover were beneficial to decrease mean crack spacing and maximum crack width, whereas reinforcement diameter had little influence on these characteristics. Predictions of crack width by existing FRC/UHPC codes were evaluated and compared with the experimental results. The comparisons indicated that predicted values by NF‐P18‐710, MC 2010, CNR‐DT 204, and RILEM TC‐162‐TDF models showed a good accuracy with experimental ones. The highest deviation for mean crack spacing and maximum crack width were less than 18 and 8%, respectively. However, CECS 38 model gave the largest deviation about 60 and 25% for prediction of mean crack spacing and maximum crack width, respectively. Among them, NF‐P18‐710 model exhibited the best accuracy with average ratio and SD of 1.01 and 0.17, respectively.

中文翻译：

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超高性能混凝土梁的弯曲开裂性能试验研究

通过实验研究了超高性能混凝土（UHPC）梁的弯曲开裂行为。测试并分析了八根UHPC梁的裂缝模式，裂缝间距和荷载裂缝宽度曲线。测试变量包括增强比，增强直径和UHPC覆盖层厚度。结果表明，UHPC的裂纹宽度随施加载荷的增加而线性增加，直到钢筋屈服为止。当施加的载荷超过屈服载荷时，一个或两个挠性裂纹发展为局部裂纹，随后裂纹宽度迅速增加。此外，增加钢筋比例和适当减小UHPC覆盖层的厚度有利于减小平均裂纹间距和最大裂纹宽度，而钢筋直径对这些特性影响很小。评价了现有FRC / UHPC代码对裂纹宽度的预测，并将其与实验结果进行了比较。比较结果表明，NF-P18-710，MC 2010，CNR-DT 204和RILEM TC-162-TDF模型的预测值与实验模型显示出良好的准确性。平均裂纹间距和最大裂纹宽度的最大偏差分别小于18和8％。然而，CECS 38模型给出的最大偏差分别为60％和25％，分别用于预测平均裂纹间距和最大裂纹宽度。其中，NF-P18-710模型的平均比和 比较结果表明，NF-P18-710，MC 2010，CNR-DT 204和RILEM TC-162-TDF模型的预测值与实验模型显示出良好的准确性。平均裂纹间距和最大裂纹宽度的最大偏差分别小于18和8％。然而，CECS 38模型给出的最大偏差分别为60％和25％，分别用于预测平均裂纹间距和最大裂纹宽度。其中，NF-P18-710模型的平均比和 比较结果表明，NF-P18-710，MC 2010，CNR-DT 204和RILEM TC-162-TDF模型的预测值与实验模型显示出良好的准确性。平均裂纹间距和最大裂纹宽度的最大偏差分别小于18和8％。然而，CECS 38模型给出的最大偏差分别为60％和25％，分别用于预测平均裂纹间距和最大裂纹宽度。其中，NF-P18-710模型的平均比和SD分别为1.01和0.17。